Unit heater



D 3, 1946- H. B. HoLTHousE 2,412,088

UNIT HEATER Filed Nov. 12, 1941 y '7 Sheets-Sheet 1 Dec. 3, 1946. H. B.HoLTHousE- UNIT HEATER 7 Sheets-Sheet 2 Filed Nov 12. 1941 ll l/ Dem 3,1946.

HOLTHOUSE UN I T HEATER Filed Nov. l2, 1941 7 Sheets-Sheet I5 Dec. 3,1946. H. B. HQL'rHousE 2,412,088

UNIT HEATER l Filed Nov. 12, 1941 'r sheets-sheet 4 l?" 'N n Dec. 3,1946. H.B. HoL'rHousE.'

UNIT HEATER Filed Nov. 12, 1941, 7 heats-sheet 5 Dec. 3, 1E46.`A H. B.HoLTHous 2,412,088

UNIT HEATER Filed Nov. 12, 1941 7 sheets-sheet e De.3,1946. Hamm-HOUSEy' 2,412,088

v UNIT 'HEATER Filed Nov. 12, V15241 'I sheets-sheet 7 gli" .111111 jab|||||||IIIICQ Patented Dec. 3, 1946 UNIT HEATER Harry B. Holthouse,Chicago, Ill., assignor to Galvin Manufacturing Corporation, Chicago,Ill., a corporation of Illinois Application November 12, 1941, serialNo. 418,774

(ci. 12e-11o) 11 Claims. l

This invention relates generally to air heating systems and inparticular to a self-contained air heating unit including a burner ofinternal combustion type operated in conjunction with an internalcombustion engine and assembled with the engine as a portable unit toprovide for thev supply of heated air at any desired location.

It is an object of this invention to providel an improved air heatingsystem.

Another object of this invention is to provide a portable air heatingunit which is compact in assembly, simple and rugged in construction andeilicient in operation to deliver a relatively large volume of air at ahightemperature to a source remote from the heating unit; v

A further object of this invention is to provide a portable air heatingunit capable of heating an airplane engine for starting purposes in aminimum of time.

Yet another object of this invention is'to provide a self-contained airheating unit for heating airplane engines having means providing for its.being simply and easily moved about under all weather conditions;

A still further object of this invention is to provide a duct system forheating airplane engines which is carried in the airplane wingsandhaving a common inlet adapted tobe operatively connected with asource of heat when the plane is stationary.

inthe provision of a portableheating unit including a heater of internallcombustion type operated in conjunction with an internal combustionengine which is light in weight, and composed entirely of preassembledparts compactly and conveniently arranged, but 'individually re.-movable from the unit to facilitate work on the unit With the unit partsof a preassembled construrtion a complete part can be carried forreplacement purposes so that the unit may be operated with but a minimumof lost time.

' Anoth'er feature of this invention is found in the provision of a ductsystem for carrying heated air to the engines and cabin of an airplanewhich is carried in the leading edge of the airplane wings and providedwith a commonoutlet for operative connection with a source of heat whenthe plane is stationary. In flight means-are provided for covering theinlet so that the heat developed by the engines is fed through the ductvsystem to provide a de-icing action at the leading edge of the Wings. 1A

Further objects, features and advantages of A this invention will becomeapparent from .the fol- A particular feature of this invention is foundlowing description when taken in connection. with the accompanyingdrawings in which:

Fig. 1 is a perspective view showing one form of the invention asapplied to the heating of the engines of an airplane for startingpurposes, the heater for the purposes of illustration being shownenlarged relative to the size of the airplane;

Fig. 21S-a fragmentary lsectional view of the inlet to the airplane ductsystem shown in Fig. 1 showing the positioning of a cap thereon when theairplane is innight; t

Fig. 3 is a plan view of the complete heating unit shown in Fig.1;

Fig. 4 is a side view of the heating unit of Fig. 1 with the engineremoved therefrom;

Fig. 5 is a. sectional view of the heating unit as seen along the line5-5 in Fig. 3;

Fig. 6 is a sectionalrview as seen along line 6- in Fig. 5 showing fuelvaporizing means used in the operation of thel heater or burner portionof the complete heating unit;

Fig. 7 is a plan view of another form of a complete heating unit;

Fig. 8 is a side view of the heating unit of Fig. 7;

Fig. 9 is a sectional view as seen along the line 9-9 in Fig. 7 showingthe construction of the. heater combustion chamber;

Fig. 10 is a sectional view taken along the line Ill- I0 in Fig. 7;

Fig-.11 is a side elevational view of another modified form of theinvention; f

Fig. 12 is an end elevational view as seen lookingtoward the right inFig. 11;

Fig. 13 is a sectional view taken along the lineV a carriage or likeportable means with the heater l extending longitudinally of thecarriage and thek engine disposed laterally to one side of the heater.VA fuel tank for supplying fuel to both the heater and the engine isarranged laterally to the same side of the heater as the engine and insubstantial alignment with the engine on an axis substantially parallelto the longitudinal axis of the heater. The longitudinal length of thecomplete heating unit is dened substantiallyby the longitudinal length`of the heater so that the unit is capable of being compactly andconveniently assembled in a relatively small space. The engine includesa fan mounted on the crank shaft thereof to provide air for burning inthe heater andair for circulating through a passage in the heatervarranged in thermal relation with the heater1 combustion chamber. Theengine and fan assembly, the heater, and the fuel tank are separatelyremovable from the portable means as preassembled units to facilitateassembly and' service work on the heating unit.

With reference to the drawings, one form of the heating unit of thisinvention is shown in Figs. 3 and 4 as including a burner or heater I0of internal combustion type, an air cooled internal combustion engine II and a fuel tank I2 coinmon to the engine and heater. These three partsare mounted on a common sled orportable supporting member I3, butindividually secured thereto; securing straps I8' and I2' being used forthe heater I and tank I2, respectively, while the base (not shown)y forthe engine II is supported directly on the sled or base member I3.

The'heater I6 is comprised of a substantially cylindrical housing memberI4 having a combustion chamber I5 and an air chamber I6 therein. Thecombustion chamber I5 has a tubular outer wall I1 closed at one end by acover plate I8 and at its opposite end I9 by the base portion 2| of asubstantially cup-shaped member 22 which defines the air chamber I6. Theopen end of the member 22 is closed by a cover or end plate 23 for thehousing member I'4. Thus as is evident from Fig. 3 the air chamber I 6and combustion chamber I5 are in alignment axially of the housing I4 andseparated from eachother by the base portion 2 I of the cup-shapedmember 22. heater housing I4 by ns 24 angularly spaced about thecombustion chamber I5 and extending axially thereof, to provide anannular passage 26 about the chambers I5 and I6 (Fig. 5). An inlet 21 tothe passage 26 is at one end 25 of the housing I4 and an outlet 28therefor is at the' housing end 29. As shown in Figs. 3 and 4 thehousing end 29 is of substantially bell shape and adapted for releasableconnection with a flexible air conduit 3| for conducting the heated airto a source remote from the heater. Air to be heated is circulatedthrough the passage 26 by a. fan 32 mounted on the engine crankshaft 33aswill be later described. V

The combustion chamber I5 (Figs. 3 and 5) is divided into 'four axiallyextending passages 34a- 34d by' a partition member 36 of substantiallyX-shape and of a construction providing for the connecting of such fourpassages to form a. single serpentine passage. The partition member 36is coextensive in length with the combustion chamber I5 and is retainedtherein in an assembly position by welding or like means to the fins 24.By virtue of this construction of the continuous passage in thecombustion chamber I5, the inlet 31 and outlet 38'of the passage areboth located in the base portion 2Il of the cupshaped member 22.

Located within the air chamber I5 and at the inlet 31 to the combustionpassages 34a- 34d is a fuel conditioning unit (Fig. 6) designatedgenerally as 39 and including a substantially tubular shaped' housing 4Iclosed at one end 42 and open at its opposite or outlet end 43 for fluidconnection with the combustion chamber passage 34a. As is evident fromFig. 6 the greater part of the conditioning unit 39 extends into the airchamber I6. vThe housing member 4I is -constructed of a high heatconducting material and includes an air and fuel mixing chamber 43a atthe closed end thereof, and an equalizing chamber 44 adjacent thereto,the mixing chamber 43a and equalizing chamber 44 being sepafrated-by aheat conducting partition plate 46 having perforations 41 over the upperportion thereof. The equalizing chamber 44 in turn is separated from thecombustion passage 34a by a heat insulating plate 48 having perforations49 arranged peripherally therein. Positioned axially through the housingmember 4I and supported y in the housing end 42, and partition plates 46and 48 is a heating element or conduit portion 5Iv having an inlet end52 extending from the'housing end 42 and an outlet portion 53 projetcingoutwardly from the open housing end 43 into the combustion passage. 34a.

Arranged in a spaced concentric relation about K nected passages 45, 50,and 55 by a substantially L-shaped bafile plate 59a adapted to directthe exhaust gases entering the conduit 54 from the axially in anopposite direction into the inlet 52 These two chambers are spaced fromthe of the heating element 5I, from where it is discharged through theheating# element outlet 53 into the combustion passage 34a. As indicatedby the arrows in Fig'. 6 this directed flow of the exhaust gases occursby virtue vof the gas passing successively through the passages 45,56and 55 and thence into the inlet 52 of the heating element 5I. Since thehousing member 4I, partition plate 46 and heating element 5I are'constructed of a material having high heat con-'- ductivity, the heatfrom the engine exhaust gases passingv about the housing 4I is readilytransferred to the heat conditioning yunit 39 for a purpose now to beexplained.

Thev fuel conditioning unit 39 is provided with an inlet 6U at theclosed end 42, thereof, in which is positioned an air and fuel nozzle59. As seen from Figs. 5 and 6' the nozzle 59 hasl one end 65 thereofextending through the conduit 54 into the air chamber I6. The end of thefuel nozzle 59 is connected through a pipe 6I with a fuel pump 62operatively supported on the engine II, and in fluid connection with thefuel tank I2 through pipe 63. The pump 62 is common to both theengine IIand heater I0 so as to supply fuel to both thereof during-the normaloperation of the heating unit. The fuel from the nozzle 59 is introducedinto the mixing chamber 43 of the fuel conditioning unit 39 togetherwith combuschamber I6.

through the apertures neat insulating plate u into the combustionpassage 34a. This vaporous mixture is mixed with the exhaust gases fromthe heating element outlet 53 for burning therewith in the combustionchamber I5, combustion being initiated by spark means S .positioned inthe combustion chamber passage 34a. and connected in operativeassociation with the engine magneto (not shown). Supplementary air `for.combustion is supplied through ports connecting the passage 34a withthe air chamber I6, and tubes connecting the passage 34e with theexhausted from the combustion passage outlet 38 into the tail pipeassembly 1K6V for discharge with an inlet 68 and an outlet or mouth 69.'I'he inlet 1| (Fig. 4) to the air chamber I6 is positionedwithin theinlet 21 lto the annular passage 26, with the mouth 69 of the fanhousing 61 being movable within the inlet 21 to the passage 26 andreleasably connected therewith. By virtue of this construction the airdelivered by the fan 32 is divided so that a portion thereof is suppliedt0 theair chamber I6, and the remaining portion circulated through theannular passage 26,` The housing 61 and fan 32 are preassembled with theengine II so as to be movable therewith as aunit, The heater or burner|0 is completely preassembled independently of the engine and fanassembly, and tank I2, with each of these three pre-assembled unitsbeing separately secured to the base member I3, as above described.Since vthe connection of the fan scroll 61 with the air inlet portion 21of the heater I0v is accomplished equally well regardless of whether theoutlet 69 is inserted Within the inlet 21, or the inlet 21 is tted aboutthe outlet 69, each partmay be removed from the base I 3`independentlyof the other to facilitate assembly and service work on the heater.

From a consideration of Figs. 3 and v4 it is seen that the burner I0 ispositioned longitudinally of the base or supporting member I3 with theengine and fan assembly disposed laterally to one side and at the end,25 thereof. The fuel tank I2 is arranged laterally to the same side ofthe heater I0 and in alignment with the engine Il on an axissubstantially parallel to the longitudinal axis of the heater I0. Thisarrangement of the heater |0, engine II, and fuel tank I2 provides for acompact assembly of the heating unit in a confined space, the height andlength of which is determined essentially by the height and length ofthe heaterl I0 and the width by the combined dimensions of the heater I0and engine il laterally of the heating unit. Since The gases fromcombustion are.

embodiment, as determined by the combined dimensions of the heater I0and engine II laterally of the heating unit is twenty-four inches. 'Ihisembodiment includes an internal combustion engine rated at about onehorse -power'and a half, with the heater and engine having a fuelconsumption during a run of one hour under'full load conditions of 2.3gallons. The fuel tank I 2 is relatively largefor an engine of this sizeand has a capacity of about 8 gallons. The fan 32 is capable ofdelivering about 1100 cubic feet per minute from the heater outlet 28when running at a speed of about 3600 R. P. M., the temperature of theheated air at the outlet 28 during normal op-v eratingconditions beingabout 140 C. Theentire weight of the complete heating unit including thebase I3 does not exceed 270 pounds so that the unit can be moved aboutrather easily by one man by sliding the base I3, The relatively solidassembly arrangement of the heater I0, engine II and fuel tank I2 adaptsthe heating unit for installation in a minimum of space, the low heightof. the unit providing for a low center of gravity which increases theease with which the unit can be handled and moved about without dangerof tipping over, and also serves to retain the unit more rigid duringits operation so as to reduce excessive vibration thereof.

The portability of the heating unit under some conditions of itsoperation, such as where .it is utilized for the heating of airplaneengines, may be facilitated by providing the base I3 with wheels |20(Figs. 3 and 4). The wheels |20, a pair of which is illustrated, may belrubber-tired and are rotatably supported at the end |2I of the basemember I3 on mounting means including a bracket or brace |22 having oneportion thereof secured to the base member I3, and the other portion 23thereof extending outwardly from the engine shaft 33 extends parallelwith the longitudinal axis of the heater I0, the fan. 32 for the heaterI0 and fan unit 11 for coolingv the engine |I are also positionedy inalignment on an axis substantially parallel to the longitudinal axis ofthe" heater I 0, with the two fans 32 and 11 and exhaust conduit 58 allbeing` arranged within the dimensions of the base I3. In one embodimentof the invention the overall heightof the heating unit is less than 15inches'and of a length not exceeding four feet, these dimensionsdefining substantially the corresponding dimensions of the heater I0.The transverse dimension of this unit on the wheels.

' for use. y sled or base member I3 beco'mes inconvenient the base end|2| in a direction inclined upwardly from the longitudinal plane of thebase member. The longitudinal extent of the portion |23 is proportionedrelative to a corresponding wheel |20 such that the wheel is liftedabove the ground, when the base member is in a horizontal position. Inother words the wheel is in substantially a clearlnglposition relativeto the ground when the heating unit is being slidably moved about on thebase member I3. By virtue of this assembly the wheels |20 are fixedlyretained in j an operating positionvso as to be constantly ready Whensliding of the heating unit on the or difficult the heating unit may bewheeled about on'the wheels |20 by simply raising or lifting the baseend |24, a handle |26 being provided for this purpose. The handle |26 isof substantially U-shaped configuration with the legs |21 thereof beingslidably supported in brackets |28 so as to be extensible from the -basemember. portions |29 at the Afree end of each leg member I21- preventthe handle |26 from being pulled out of operative connection with thebase member I3. On lifting of the base member end |24 the wheels |20 arelowered into engagement with the ground, with the continued raising ofthe base member resting the entire weight of the heating the base memberend |24 is accomplished with the wheels |20 functioning as a pivot pointso that the unit is gradually lifted and lowered to completely eliminateany sudden dropping thereof. The heating unit is thus capable of beingslidably moved about on the base I3, or wheeled about on the wheels |20with equal facility since Stop The lifting Aand lowering of 'A unit areequally vtrated in Fig. 1 applied to the heating of airplane engines forstarting purposes. The airplane is shown as including a fuselage 18having wings 18, with each wing 18 carrying a pair of engines-88 and 8|thereon enclosed by a cowl 88. The plane cabin 82 is disposed betweenthe wings 18 and in the fuselage 18- in a usual manner. A duct 83 ispositioned transversely of the cabin 82 and at the leading edge of eachwing 18, the opposite ends of the duct terminating substantialLv atthewing ends the outermost engines 8| within a corresponding cowl 88. As isclearly shown in Fig. 1 the duct 83 is of a reduced section afterleaving the inner engines 88, with outlets 88 and 88 being providedinthe duct 83 at the inner engines 88 andouter engines 8 I, respec-,arranged substantially intermediate the inner engines 88 and below thecabin 82 and is adapted for operative releasable connection with theheater I8 through the exible conduit 3|. This operative connection maybe of the usual bayonet type. A duct portion 88 is attached to the duct88 for carrying heated air into the cabin 82. With the duct system inthe plane connecting the engines and cabin, heat is readily suppliedthereto by simply connecting the heater |8 to the inlet 81. v

By virtue of the arrangement of the duct'83 in the wings 18 and at theleading edge of such wings, it may be utilized during normal flyingoperation to provide a de-icing means. Thus when the plane is in flighta cover or cap means |8| (Fig. 2) having pins |32 for bayonet assemblywith corresponding slots |33 in the inlet 81,

. is positioned over the inlet to plugthe same.

With the inlet 81 stopped a portion of the air within the cowls 88heated by the engines is fed into the duct 88 to heat the same,circulation of the air in the duct being accomplishedV by the severalopenings therein at 88 and 88.

In Figs. 7-10 there is shown a heating unit which is substantallysimilar in all respects to the heating unit of Figs. l6, except for somechanges in the construction of the burner, the heating unit of Fig. 7being somewhat larger than the heating unit of Fig..2 so that the burnerthereof is constructed to provide for a relatively higher output ofheated air. Similar numerals of reference primed shall be used,therefore. in Figs. '1-10 to indicate parts thereof corresponding toFigs. 1 6.

Referring to Figs.l '7 and 9, the heater or burner I8 is seen to includea housing member 88 of substantially rectangular form and having an openside 8| which is supported directly on the base member i3. Enclosedwithin the housing 88 are a combustion chamber i8' and an air chamberI8', these two chambers being of a substantially rectangularcross-section and arranged longitudinally of the housing member 88 butspaced therefrom by radiating fins 82.- The fins 82 are substantiallyco-extensive in length with thefcombustion chamber I8' and form an aircirculating passage 28 thereabout having an inlet 21' and an outlet 28.As is best seen in F18.

Y 9 the fins 82 at the bottom ofthe heater I8' serve to space thechamber I8' from the base member flning walls for the air circulatingpassage 28'. The combustion chamber I8' (Figs. 9 and 10) is dividedlongitudinally by partition members 88 into four passages 8|a-8Id whichare interconnected to provide a continuous pe through the combustionchamber i5'. These passages are, of a size to provide for the use of apair of inlets 31 leading to the passage 8|avand a pair of outlets 38leading from the passage 8|d. Each inlet 31' is operatively associatedwith a fuel conditioning unit 38 which is similar in all respects to theVunit 38 fully described above in connection with Fig. 6. In turn, eachoutlet 88' is provided with an exhaust tail assembly 18 whichis similarto the corresponding assembly of Fig. 3. The two fuel conditioning units38 in the inlets 31' are operated concurrently with only Vone spark Sbeing needed to initiate combustion.

'I'he engine Il and fuel tank I2' operatively associated with the heateri8', are correspondingly larger than the like parts in the heating unitof Fig. 3 but are relatively arranged and operated in all respectssimilar thereto. A further description thereof is believed, therefore,to be unnecessary. Because of the relatively low or pancake assembly ofthe complete heating unit, a

platform or shelf 82a (Fig. 8) may be supported heating unit, theplatform 82 is relatively low.

so that a second heating unit can be very conveniently positionedthereon without being too high to operate or service. It is obvious, ofcourse,

that a similar platform structure is' also applical Ible for usewith'the heating unit of Fig. 3`.

An arrangement of the heating unit of Figs. l6

with the engine and i2 in a superposed rela-,

tion with the heater I8 is shown in Figs'. 1p1-14. The base I8 isprovided with a frame structure erally outwardly from the unit. Exceptfor the trays 8.1 and 88 the sides and ends of the frame structure areentirely open, a top |82 providing a cover for the heating unit andfunctioning also as a'brace for the uprights 88. The outlets '28a of theair passage in the heater, three of which are used in the heating unitof Fig. 11, are thus readily accessible for operative connection withflexible conduit means 8|.

'I'he heater I8 is secured directly to the base I8 by mating gussetplates |88 (Fig. 13) of semi- 'circular shape andladapted together toextend completely about the heater |8. The pairs of mating lplates |83are spaced longitudinally of the heater and in their mating assemblyprovide supporting legs |88 at the bottom of the heater, and alongitudinally extending platform portion |88 at the top thereof. Asshown in Fig. 11 the platform portion |88 at the heater end 28 isadapted to alone support the engine thereon, with the remaining top'portions |88 serving as supports for the fuel tank l2. The scroll 81 forblower or air .circulating fan 32 is\carried directly on the top of theheater at the end 281 thereof.

. 9 The scroll 61, thev engine I|, and the fuel tank I2 are thuspositioned in longitudinal alignment laterally ofthe heater I anddirectly thereabove, with the engine II located between the scroll 61and the fuel tank I2, but with all of these parts confined within thelongitudinal length of the heater I0. By virtue of this assembly of theheating unit the over all length of the heating unit is deiinedsubstantially by the'length of the heater I0, while the width thereofIis determined substantially by the transverse dimension or diameter ofthe heater I0.

With reference to Fig. 14 the heating unit of Fig. 1l is shown with a.platform structure |01, in place of the gusset plates |03, forsupporting the engine II and fuel tank I2. The platform |01 is carriedon upwardly extending frame members positioned at the ends and to eachside of the heater I0 and extending upwardly from the base I3 to aposition immediately above the heater I 0. The engine4 II and fuel tankI2 are suitably mounted on the platform |01 in alignment on an axissubstantially parallel to the longitudinal axisof the heater I0, theengine I I Abeing positioned between the fuel tank I2 and the fan scroll61 which is supported directly on the heater I0.

As previously mentionedl side trays. 91 and 98 are extendedlongitudinally of the heating unit and pivotally supported from theuprights 96. The trays 91 and 9 8 in their open positions, as indicatedin dotted lines in Fig. 12, are adapted to receive therein the ilexibleconduit means 3| corresponding to the three outlets 28a (Fig. 11i eachyconduit when deiiated being foldable into a compact bundle. With theconduit means in a folded condition within a corresponding tray, thetrays are closed against the heating unit so as to appear as a sidethereof, as shown in full lines in Fig. 12. The flexible conduits arethus completely out of the way when the heating unit is to betransported or moved about, and immediately available simply by thepivotal moving of the trays laterally outwardly from the heating unit. v

The maneuverability of the heating unit for all weather conditions isfacilitated by the proviare thus removed entirely Within the confines ofthe frame structure 95 whereby to increase the ease in handling theheating unit for moving'it about on the base or sled member I3'. Whenthe wheels |08 are in an operating position the heating unit ismaintained substantially level bv the provision of a pivotal end supportor foot. |09 pivoted to the sled member I3' at III. As shown in Fig. 11the foot member |09, is pivotally movable in a counter-clockwisedirection to its dotted line position on the top of the sled membervI3'. In its unit supporting position the foot member |09 is moved to itsfull line position and retained therein by a clip member II2 secured atits end I I3 to the base member I3' and open at its opposite end I I4 toprovide a slotted recess for receiving the foot |09.

From a consideration of the above description and drawings. it is seenthat the invention prov vides a portable self-contained heating uniteomposed of a burner an internal combustion engine for startingpurposes.

that in cases of emergency, the engines must be 10 for operating theburner, and a fuel tank common to both theburner and the engine, each ofwhich is of a preassembled construction and adapted for individualmountingon a common unit are interchangeable, they may be kept` in stockin their preassernbled form so as .to be readily substituted forcorresponding parts which require servicing. The hea-ting units are thusadapted for heavy duty service since a part requiring attentioncan beworked on while the corresponding workable part is in operation.V

The overall heating unit is very compactly ary ranged and capable of ahigh heat outputsoas to make it particularly applicable for use inheating the engines of transport or bombing planes It is readilyappreciated of lboth vsled and wheel means which are equally availablefor use. The heating unit of this invention is entirely complete withinitself and its operation is initiated concurrently with the operation ofthe internal combustion engine associated therewith. It is apparent, ofcourse, that the heating unit may be retained 4in operation While it isbeing transported or moved about so that it need be started onlyV onceregardless of the number of engines to be heated or the location of theplanes carrying these engines.

Although specific reference has been made to the use of this inventionfor heating airplane engines. it is to be understood that this is onlyone application thereof, and that the heating unit may be satisfactorilyused for the -heating of cabins, tents, and auto trailers or the like.

Further, although the present invention has been described with speciiicreference to several preferred embodiments thereof, it is to beunderstood that it is not to be so limited since changes Y can be madetherein which are within the full intended scope of this invention asdefined by the appended claims.

I claim: I

1. A portable air heating unit having a base member for supporting aburner of internal combustion type and an internal combustion engine foroperating said burner, a fuel tank common to said burner and engine,housing means for said burner having therein a combustion chamber and apassage for the air to be heated in thermal relation with saidcombustion chamber, said housing means having a length substantiallyequal to the longitudinal length of said base, means driven by saidengine for supplying fuel from said fuel tank to said combustion chamberand engine, air moving means operatively connected with said engine forsupplying air to said combustion chamber and air passage. meansoperatively associated with said combustion chamber for vaporizing thefuel supplied'thereto for mixing together with vthe air for combustion,and conduit means for the exhaust gases from .said engine arranged inthermal relation with said fuel vaporizing means to heat the same, saidengine and fuel tank being positioned in substantial alignment on anaxis substantially parallel to the longitudinal axis of of said portablemeans, an internal combustion engine for operating said heater, a. fueltank common to said heater and internal combustion engine, said heaterhaving a passage therein for air to be heated, means driven by saidengine and fluid -connected'with said tank for supplying fuel to saidengine and heater, air moving means operated by said engine forcirculating air to be heated through said passage and supplying air forcombustion to said heater, means in said heater for vaporizing the fuelsupplied-to said heater for' mixing together with said combustion air,with said engine and fue1 tank being po'sitioned in substantialalignment on an axis substantially parallel to the longitudinal axis ofsaid,

heater, and means supporting all of said heater, engine, fuel tank andair moving means substantially within the dimensions of said portablemeans.

3. A unit for heating air including a longitudinally extending heater ofinternal combustion type adapted for operation in conjunction with aninternal combustion engine having a fuel tank, said heater includingmeans defining a combustion chamber. said enginev being disposed at oneend of said heater and said fuel tank being disposed at the opposite endof said heater, means supporting said engine and tank in` alignment onan axis substantially parallel to the longitudinal axis of said heaterand substantially within the longitudinal length thereof, said heaterincludingmeans defining a passage for air to be heated arranged inthermal relation with said combustion chamber, aix'- moving meansoperatively con nected with said engine for circulating air through saidpassage.'conduit means fluid connecting said air moving means and saidair passage, means in said conduit means for by-passing a portion of theair delivered by said air moving means to said combustion chamber,andmeans for supplying fuel to said combustion chamber-'and engine fromsaid tank including fuel moving means common to said heater and engineand operatively connected with said engine.

4. A system for heating air including a burner of internal combustiontype adapted for operation in commotion with an internal combustionengine land operatively assembled therewith on a common mounting meansfor transportation as a unit, a housing member for said burner havlng acombustion chamber therein and an air -passage arranged in thermalrelation with said combustion chamber, air moving means operated by saidengine for delivering air to said burner and air passage, a fuel systemfor said burner and engine including `a fuel tank carried on saidmounting means and pumping means operatively supported on said engine,means-supporting said fuel tank, engine and air moving means in alignment to one side of said housing member and within the distance definedsubstantially by the longitudinal `length of the housing member, with .lthe vertical height.v of said transportable unit being definedsubstantially bythe vertical height vof said housing member.

fil

with an internal combustion engine, common supporting means for saidengine and burner, a housing member for said burner having a combustionchamber therein and a passage for air to be heated arranged in a thermalrelation with said' combustion chamber, means for supplying fuel to saidengine and combustion chamber including a fuel tank carried on saidsupporting means, air moving means in driven connection with saidengine, and means dividing the flow of air from said air moving means tosaid combustion chamber and said air passage, means supporting said airmovingmeans, fuel tank, and engine in substantial alignment laterally toone side of said burner, with the longitudinal length and verticalheight of said unit being defined substantially by the correspondingdimensions of said burner, and the dimensions of said engine and fueltank laterally of said burner being substantially equal so as to providefor a substantially uniform width of saidunit over the complete lengththereof.

6.' A unit for heating air including a burner of internal `combustiontype Aadapted to be operated in conjunction with an internal combustionengine having a fuel tank and conduit means for exhaust gases, a housingmember for said burnerv having therein a combustion chamber and an airpassage arranged in thermal relation with said combustion chamber, saidengine and fuel tank being disposed laterally to one side of saidhousing, meanssupplying fuel to said combustion chamber from said fueltank, air moving means operated by said engine for delivering air tosaid combustion chamber and air passage, heat transfer means in saidhousing member adapted to utilize the exhaust gases from said conduitmeans to prepare the air and fuel supplied to said comy 5. A portableair heating unitincluding a longitudinally extending burner ofinternalcombusnon type adapted for operation in conjunction bustion chamberv forburning therein, means for carrying the exhaust gases in said conduitmeans into thermal relation with said fuel preparing means, and portablemeans for said unit including a mounting member adapted to carry saidengine, burner and fuel tank in their above-defined relative positions,with the longitudinal dimension of said mounting member being denedsubstantially by the length of said housing member, and the lateraldimension of said mounting member substantially by the combineddimensions of said housing member andengine laterally ofsaid unit, withsaid fuel tank, housing mem; ber and engine all being confined withinthe dimensions of said mounting member and within a verticaldimensiondefined substantially by the vertical height of said housing member.

7. An air heating system having a burner of internal combustion type andadapted for` opera- .tion in conjunction with an internal combustionengine. a portable base member adapted to carry said burner 'and engine,housing means for/said burner having the lower side thereof open andpositioned against said base member, a combustion chamber within saidhousing means spaced from said base member and housing means to formanair passage, means operated by said engine for supplying air to saidcombustion cham? ber and air passage, a fuel system for said burner andengine including a fuel tank, and means supporting said engine and fueltank in substantial alignment between opposite ends of said housingmeans and'on an axis substantially parallel with the longitudinal axisof said housing means.

8. An air heating unit including portable means for carrying a burner ofinternal combustion l type and an internal combustionengine opera- 13tively associated with said burner, with said burner being of apreassembled construction and including a housing member having thereina combustion chamber and a passage forv air to be heated arranged inthermal relation with said' side of said burner, and means forindependently securing said burner, eng1ne,'and fuel tank on saidportable means so that each of said three lparte'. is separatelyremovable from said portable means, y

9. A portable air heating unit including a heater of internal combustiontype operated in conjuncytion with an internal combustion engine, saidheater having a combustion chamber and a passage for air to be heatedthermally related with said combustion chamber, a supporting member forsaid heater, a fuel tank common to said en` gine and heater, a pluralityof means for securing said heater to said supporting member, saidsecuring means being spaced longitudinally of said heater with eachthereof having a portion positioned at the top of said heater, with at,least one of said top portions serving as a support for said engine, andat least another of said top portions serving as a support for saidtank, air moving means operatively connected with said engine forsupplying air to said combustion chamber and air passage, and means formovingfuel to said engine and combustion chamber from said fueltankoperatively supported on said engine, with said fuel tank, engineand air moving means being confined substantially within thelongitudinal length of said heater, and said heater defining lLtelongitudinal length of said supporting mem- 10. A portable air heatingunit including a heater of internal combustion type operated solely byan internal combustion engine, said heater having a combustion chamberand a passage for air to be heated thermally related with saidcombustion chamber, a basev member for supporting said heater, framemeans secured to said base member and extending upwardly therefrom aboutsaid heater, a mounting member carried on said frame means above saidheater for supporting said engine, a Vfuel tank common to'said heaterand engine supported on said mounting member, air moving meansoperatively connected 'with said engine for supplying air to saidcombustion chamber and air passage, and means for supplying fuel to saidengine and heater from saidfuel tank operatively supported on saidengine, with said fuel tank, engine and air moving means being arrangedY substantially within the longitudinal length of said heatenand saidbase member and mounting member being substantially co-exteny sive inlens-th with said heater.

11. A heating system including a longitudinally extending burner and apower unit, said burner being 'of the internal combustion type' andadapted for operation in conjunction with said power unit andoperatively assembled therewith on common mounting means fortransportation as a unit, said burner having a combustion chambertherein, means forming a passage for air to be heated arranged aboutsaid combustion chamber, andin heat conducting relation therewith, afuel supply system including a fuel tank and means operated by saidpower unit for delivering fuel to said combustion chamber, air movingmeans operated by said power unit, means for dividing the flow of airfrom said air moving means to said combustion chamber and said airpassage, and means supporting said airmoving means, fuel tank and powerunit in substantial alignment on an axis substantially parallel to thelongitudinal axis of said burner and substantially within thelongitudinal length thereof.

v HARRY B. HOLTI'HOUSE.-

